The clinical relevance of KRAS gene mutation in non-small-cell lung cancerTímár, JózsefCurrent Opinion in Oncology: March 2014 - Volume 26 - Issue 2 - p 138–144 doi: 10.1097/CCO.0000000000000051 LUNG AND MEDIASTINUM: Edited by Robert Pirker Abstract Author Information Purpose of review There are conflicting data on the potential prognostic and predictive role of mutant KRAS in non-small-cell lung cancer (NSCLC). Recent findings KRAS is the most frequently mutated oncogene in lung adenocarcinoma patients of non-Asian ethnicity. Novel data also revealed that allelic variants of mutant KRAS are different concerning their biochemistry, which may influence their prognostic and predictive role in NSCLC. Though mutant KRAS is not the target of molecular therapy yet, a molecular diagnostic algorithm involving KRAS determination can define a subgroup of tumors where no further diagnostic test is necessary due to the exclusivity of this driver oncogene mutation. Recent data indicated that the prognostic role of mutant KRAS in lung adenocarcinomas in Asian patients is evident, while more research is neccessary in non-Asian populations. Studies also suggest the potential predictive role of mutant KRAS in the context of chemosensitivity of NSCLC which may depend on the individual drug types. Recent data on the negative predictive role of KRAS mutation on the efficacy of EGFR tyrosine kinase inhibitor (TKI) therapies confirm previous findings. Summary Studies on the prognostic and predictive role of mutant KRAS in lung adenocarcinoma must be extended to the analysis of the potential role for allelic variants. 2nd Department of Pathology, Semmelweis University, Molecular Oncology Research Group, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary Correspondence to József Tímár MD, PhD, head, 2nd Department of Pathology, Semmelweis University, Üllői 93. H-1091 Hungary. Tel: +36 1 215 6921; fax: +36 1 215 6921; e-mail: firstname.lastname@example.org © 2014 Lippincott Williams & Wilkins, Inc.